As an oral care instrument of this type, there is conventionally proposed an oral care instrument which includes washing solution supply means, and a long washing solution discharge tube attached to the washing solution supply means (for example, see Japanese Unexamined Patent Publication No. 2007-167088). In this oral care instrument disclosed in Japanese Unexamined Patent Publication No. 2007-167088, an elastic nozzle is provided at a distal end of the washing solution discharge tube, and the washing solution supply means is composed of a washing solution container having a pumping function. In addition, every time a pressing portion (button) provided on the washing solution container is pressed, the washing solution is ejected from a discharge orifice opened to a projecting end of the elastic nozzle provided at the distal end of the washing solution discharge tube through a discharge flow path in the washing solution discharge tube. Further, there is also proposed another oral care instrument which also includes washing solution supply means, and a washing solution discharge tube attached to the washing solution supply means (for example, see Japanese Unexamined Patent Publication No. 2008-132099). The oral care instrument disclosed in Japanese Unexamined Patent Publication No. 2008-132099 further includes a cleaning member, and a washing solution ejecting portion. The cleaning member is provided at a distal end of the washing solution discharge tube so as to be projected in the direction perpendicular to the axial direction of the washing solution discharge tube. The washing solution ejecting portion has a washing solution discharge orifice which communicates with a discharge flow path of the washing solution discharge tube, is opened to the external side with respect to a position in the vicinity of the base of the cleaning member, and ejects washing solution toward the projection of the cleaning member from the middle portion to the distal end thereof.
According to the oral care instrument disclosed in Japanese Unexamined Patent Publication No. 2007-167088, the washing solution can be accurately ejected toward an interdental portion with less washing solution scattered, and food debris can be surely removed from the interdental portion with the washing solution for washing. According to the oral care instrument disclosed in Japanese Unexamined Patent Publication No. 2008-132099, after dental plaque which cannot be removed with water flow only is removed with the cleaning member, the washing solution can be effectively supplied to deep portions through the cleaning member. This makes it possible to effectively sterilize and suppress inflammation of a tissue by supplying drug solution containing an antimicrobial agent, an anti-inflammatory agent, or the like to embrasures, gingival marginal portions, periodontal pockets, or the like.
However, in these conventional oral care instruments, components from the washing solution discharge tube to the nozzle portion ejecting the washing solution are integrally formed. Further, since the washing solution discharge tube is required to have strength enough to support forces received from the elastic nozzle or the cleaning member when used by a user, the washing solution discharge tube is required to have a certain size in diameter. Moreover, if the thickness of the washing solution discharge tube is decreased in consideration of the material cost, an internal space thereof is made larger to some extent. If the internal space is made larger as described above, there arise a problem that the drug solution is hard to be ejected at the start of use, and a problem that the amount of remaining drug after use is large and the risk of being contaminated from the distal end of the nozzle is increased. On the other hand, if the internal space is made too small, durability of a produced mold is made worse, and the following problem is caused. The problem is that when the gel or cream oral composition flows through the internal space of the washing solution discharge tube as a supply path, the oral composition transmitted to the supply path does not stop immediately even when the transmitting operation is stopped and thus an excess amount of the oral composition are ejected and wasted.